Projection display systems have become increasingly important for conveying and sharing information in modern society. Projection display systems that have become common include cinema projectors, rear projection TVs, and digital projectors for displaying information from computer and consumer video systems. Recently, advances in miniaturization of the components of projection systems have opened up new possibilities in projector system design, allowing smaller projectors known as mini-projectors, pocket-projectors, or picoprojectors. These miniature projection systems typically are developed around an optical projection engine. The optical projection engine is a custom component that generally includes a microdisplay panel, a light source, and optics for projecting the image on an external surface. The microdisplay panel may be manufactured according to one of several commercially viable transmissive or reflective microdisplay panel technologies including, by way of example, Active Matrix Liquid Crystal Display (AMLCD), Liquid Crystal on Silicon (LCoS), or micro-electro-mechanical systems (MEMS). Alternatively, the microdisplay may be manufactured using a light emitting technology such as Organic Light Emitting Diodes (OLEDs) or Electroluminescent technologies (EL), in which case the separate light source is not required.
Miniature projectors may display information from a wide variety of sources including desktop computers, laptop computers, netbooks, cell-phones, smart-phones, tablet computers, gaming devices, portable DVD players, digital cameras and camcorders, and/or other portable video systems. Additionally, for particular applications, users of miniature projection systems may desire that the projection system be capable of more advanced features. For example, it may be beneficial if the projection system could store video or still image data for display. It may also be beneficial if the projection system could store documents or other files in standard formats such as PDF, WORD, POWERPOINT, or FLASH. In addition, it may be desired that the user can interact with the miniature projection system through an input device. For these more advanced features, the projection system requires auxiliary system components including non-volatile storage and input devices, and a processing unit to interface with the auxiliary components and generate video from the stored image data, video, documents, or other files.
For each of these applications, a separate miniature projection system must be designed from the component blocks, including the optical projection engine, the processing unit, and the auxiliary system components. The designer must not only integrate the desired functions for the given application, but also must design the processing unit to interface with and control the specific optical projection engine. Even within the same display panel technologies, these optical projection engines may have different data interfaces and control parameters. For example, different optical projection engines may set brightness, contrast, and white point through different means. The wide variety of data interfaces and control parameters complicates the system design for each application.
Additionally, optical projection engine technology is constantly changing. Display device manufacturers, light source manufacturers, and projection optics manufacturers are constantly optimizing the design parameters of the components of the optical projection engines to reduce the size of the engine, increase light output, and reduce power requirements, among other parameters. For each new iteration of an optical projection engine, designers of miniature projection systems must redesign their system boards to accommodate the new optical projection engine design. Accordingly, the amount of system integration required to develop miniature projection systems from the ground up for each application and for each optical projection engine has presented challenges to manufacturers of miniature projection systems seeking to keep pace with the rapid change of business and consumer requirements for these types of projection systems.